1. The Tragedy of the Commons and The Prisoner’s Dilemma

2. Marie Jean Antoine Nicolas de Caritat, marquis de Condorcet
1765, he published his first work on calculus
Friends with Benjamin Franklin, Thomas Jefferson, etc.
Invented Condorcet method for voting with multiple candidates. 
Free and equal schooling for all
Equal rights for women
Equal rights for all races
Condorcet believed that humans are uniquely malleable, not predetermined by biology.
The only obstacles to our advancement are oppression, bigotry, and ignorance. 

3. Thomas Malthus 1798, writes critique of Condorcet et al
 Food supplies increase additively (linear)
Population increases geometrically (nonlinear)

4. Thomas Malthus
Malthus argued that two types of checks hold population within resource
 catastrophic checks: hunger, disease and war
preventive checks: abortion, birth control, prostitution, postponement of marriage and celibacy
God created this situation deliberately to ensure our moral development

5. Herbert Spencer Malthus proves that welfare to the poor
"A Theory of Population" (1852)
Malthus proves that welfare to the poor
is like feeding rats: you only get more rats
 Social Darwinism: humanitarian impulses should be resisted so that the social struggle for existence can remove the unfit.

6. The Tragedy of the Commons Garrett Hardin, 1968
The class of "No technical solution problems" has members. My thesis is that the "population problem," as conventionally conceived, is a member of this class.
It is fair to say that most people who anguish over the population problem are trying to find a way to avoid the evils of overpopulation without relinquishing any of the privileges they now enjoy. They think that farming the seas or developing new strains of wheat will solve the problem--technologically. I try to show here that the solution they seek cannot be found.

7. The Tragedy of the Commons Garrett Hardin, 1968
Herders sharing a common parcel of land, on which they are each entitled to let their cows graze.
It is in each herder's individual interest to put as many cows as he acquires onto the land.
A herders might be aware of overgrazing dangers, but to limit cows would just further exacerbate the decrease to income from the overgrazing.
Modern examples: overfishing of the world's oceans, timber extraction, etc. Even advertising.

8. The Tragedy of the Commons Garrett Hardin, 1968
Hardin laments this interpretation of The Universal Declaration of Human Rights (United Nations):
The Universal Declaration of Human Rights describes the family as the natural and fundamental unit of society. [Article 16[10]] It follows that any choice and decision with regard to the size of the family must irrevocably rest with the family itself, and cannot be made by anyone else.

9. The Tragedy of the Commons Garrett Hardin, 1968
Hardin essentially repeats the arguments of Hobbs:
Education is not a solution, humans need higher authority for coercion
The authority can be a government dictatorship that regulates human reproduction (communist model) or capitalist market that privatizes ownership of all resources (Spencer’s solution)

10. Hofstadter’s example:
Game Theory Approach to the Psychology of the Commons: The Prisoner’s Dilemma
Hofstadter’s example:
You have diamonds, your dealer has money.
You both agree to leave bags at designated places in forest:
You leave a full bag, but his bag is empty. You get ripped off.
You leave an empty bag, he leaves a full one. You have doubled your wealth.
You leave an empty bag, and he leaves an empty bag: no worse off than you are already.
Therefore, economic “rationalism” demands that you leave an empty bag. Since the dealer is in the same situation, you both receive nothing.

11. The Prisoner’s Dilemma
You have both been accused of a crime:
You both stay mum, you each get 2 years in jail
You rat out your partner: you are free, he gets 5
You both rat each other out, you each get 4 years in jail
“Rational self-interest” gives a sub-optimum result!

12. Origins of Prisoner’s Dilemma
RAND in 1950s: US and USSR each want to eliminate nukes
If you both reduce nukes (“mutual cooperation”) you both get safer world
If US keeps nukes (“defect”) and USSR gets rid of them (“cooperates”), US has security, USSR insecure.
If you both keep nukes (“mutual defection”), you both get insecure world

13. The Prisoner’s Dilemma is our Race to the Bottom
The Prisoner’s Dilemma applies to many situations in which lack of trust destroys our ability to cooperate
Human population: why should I have a small family to prevent over-population, if others do not?
Renewable resources: why should I limit my (grazing, hunting, fishing, pollution) if others do not?
International security: why should I reduce nukes if others do not?
Advertisements: why should I make small billboards if others make larger ones?
Sleazy crap on TV: why should I offer viewers intelligent programming if others get more views from sleazy crap?
The Prisoner’s Dilemma is our Race to the Bottom

14. The Prisoner’s Dilemma: canonical version
Two players have the choice of cooperating or defecting.
Temptation to defect is the highest payoff (5)
Reward for mutual cooperation is second highest payoff (3)
Punishment for mutual defection is third highest (1)
Sucker’s payoff (cooperating during defect) is lowest (0)
T>R>P>S and (T+S)/2 < R are required conditions
More generally, this is
A “Nash Equilibrium”

15. The Iterated Prisoner’s Dilemma:
Robert Axelrod 1979
Researchers asked to submit program that makes the Cooperation/Defect decision
Programs can keep track of each other, and change in response to prior moves
Included random, always cooperate, and always defect
Every program interacts with every other program 200 times, including a clone of itself
Scores are cumulative: it doesn’t matter how many times you “lost”—only the sum of the scores matter

16. Sample of strategies Always Cooperate -- Cooperates during every round
Always Defect -- Defects during every round
Tit-for-Tat – Starts by Cooperating, then plays whatever move the opponent played in the previous round.
Pavlov -- Starts by cooperating. If both players played the same move in the previous round (both D or both C), then C.
Mistrust -- Starts off defecting and then plays whatever the opponent played in the previous round.
Spiteful--Starts off cooperating. Once the opponent has defected, it defects for the remainder of the match.
Soft Majority--Starts off cooperating and then plays whatever move has been used most frequently by its opponent (C if equal amounts).
Hard Majority--Starts off defecting and then plays whatever move has been used most frequently by its opponent (D if equal amounts).
Hard Tit-for-Tat -- Starts off cooperating and then cooperates unless the opponent has defected at least once in the last two rounds.

17. The Iterated Prisoner’s Dilemma winner: Rapoport’s tit for tat
The first time meeting a program, cooperate
The next time, repeat what it did last time.
If T4T meets itself, they cooperate
If T4T meets defect-only, it only gets fooled once
If T4T meets random chooser (eg JOSS), it will retaliate on the next move (often when JOSS cooperates)

18. The Iterated Prisoner’s Dilemma winner: Rapoport’s Tit for Tat
Axelrod attributes the success to 3 levels of analysis
Direct effect of a choice: defection earns more
Indirect effect: you may get punished in retaliation
“tertiary effect”: unending mutual recrimination—hence the crucial importance of forgiveness

19. Spatial prisoner’s dilemma (Martin Nowak)
Runs like cellular automaton
Spatial structure allows “islands” of cooperation to rise in sea of defectors

20. Iterated Prisoner’s Dilemma Solves the problem of Evolutionarily Stable Strategies
Acorn Woodpecker: Why don’t “freeloaders” rise in genetic frequency?

21. Other Evolutionarily Stable Strategies
The Side-Blotched Lizard (Uta stansburiana) is polymorphic with
three morphs that each pursues a different mating strategy
1) The Orange throat is very aggressive and operates over a large territory - attempting to mate with numerous females within this larger area
2) The unaggressive Yellow Throat (called “sneakers”) mimic the markings/behavior of female lizards and sneakily slip into the Orange Throat's territory to mate with the females there (thereby overtaking the population), and
3) The Blue Throat who mates with and carefully guards ONE female - making it impossible for the sneakers to succeed and therefore overtakes their place in a population…